To maximize the profit, we need to find the value of
that maximizes the difference between the revenue
and the cost
, which gives us the profit function
.
Given:

The profit function is:

To find the value
that maximizes the profit, we need to find the vertex of the parabolic profit function
. The
-coordinate of the vertex is given by:

In our case,
and
so:

Now we can find the corresponding
value:
×

Calculating this:

Therefore, the maximum profit occurs when the Pear company produces and sells 8000 pPhones, and the maximum profit is $172,821,182.